POP3 and IMAP4 Proxy server

 Perdition allows users to connect to a content-free POP3 or IMAP4
 server that will redirect them to their real POP3 or IMAP4 server. This
 enables mail retrieval for a domain to be split across multiple backend
 servers on a per user basis. This can also be used to as a POP3 or IMAP4
 proxy especially in firewall applications. Perdition supports arbitrary
 library based map access to determine the server for a user. POSIX
 Regular Expression, GDBM, Berkeley DB, MySQL, PostgreSQL, ODBC and LDAP
 libraries ship with the distribution.